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Frequently Asked Questions about the Landsat Missions

Return to the FAQ

Question:
What is the geometric accuracy of a Landsat 7 ETM+ systematically corrected Level 1G processed product?

Answer:

Landsat ETM+ was designed to provide a geometric accuracy of at least 250 meters (1 sigma) in low-relief areas at sea level. However, the use of definitive ephemeris for Level 1G (systematic) correction frequently provides a geometric accuracy within 30-50 meters.

The .MTL field "ephemeris_type" will show whether a product was created with definitive or predicted ephemeris.

The Landsat 7 Image Assessment System (IAS) Geometric Algorithm Theoretical Basis Document provides more details about processing and geometric correction for Level 1G data products.